Discussion on sliver sizing of the hottest high-yi

2022-08-18
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Discussion on sliver sizing of high-yield carding machine

sliver sizing is directly related to carding yield and is an important parameter in carding process design. Because it has an important impact on carding process, it is of practical significance to explore and determine sliver sizing of high-yield carding machine

1 change of sliver weight of high-yield carding machine

see table 1-6 for the changes of carding machine output, sliver weight and sliver speed (doffer speed) at home and abroad in the past 30 years

table 7 shows the changes of average sliver weight and sliver speed of high-yield carding machines from 1970 to 2000

table 7 shows that since 1970, the sliver weight of the world's high-yield carding machines has increased by an average of 1.29 times, while the sliver speed has increased by an average of 2.9 times

according to the data in Table 1 ~ table 6, we can see that the main way for world-renowned carding machine manufacturers to increase output is to increase the cylinder speed and output speed. Limited to the scope of discussion, we will only analyze the latter

(1) Germany truzler company: from the DK carding machine in the 1970s to the DK903 carding machine now, its output has increased by 4 times, while the quantitative change is extremely slow, only 1.6 times. The output speed increases by 3.3 times

(2) Rieter company of Switzerland: from C1/2 carding machine to C51 carding machine, its output has increased by 3 times, the output speed has increased by 2.5 times, and the quantitative has increased by only 1.36 times

(3) Japan Fenghe company: from the max carding machine in the 1970s to the CMH carding machine, its output has increased by 4 times, but the sliver weight has not changed greatly. From the CMK-3 carding machine to the cm80 carding machine and the CMH carding machine, the sliver weight has not changed at all, but the output speed has increased by about 3-4 times

(4) China Qingdao Textile Machinery Factory: from A186 carding machine to fa232a carding machine, its output increases by about 4 times, the quantitative increase by 1.3 times, and the output speed increases by more than 3 times. Other companies, such as Zheng textile machinery in China, lubuska in Poland, textima in Germany, crorol in the UK (whose single and double ration are the same) all adopt the method of increasing output speed to increase output, while the sliver ration only increases slightly without major changes

(5) mazzoli company of Italy: mazzoli (Dongtai) C501 carding machine samples indicate a quantitative range of 3.3 g/m~6 g/m, 8 g/m~16g/M (it may be extruded from the B1 material market for plush because the oxygen index does not meet the requirements of Chinese specifications). In another machine sample, the quantitative range of cx300 carding machine is 3.933 g/m~5.3s/m, while the sliver quantitative range published in the user manual of CX400 carding machine is 3.37 g/m~5.83 g/m, It can be seen that the way mazoli models improve output is also mainly reflected in the improvement of output speed

now take the actual production of DK series carding machine of Germany truzler company and the carding machine of Rieter company of Switzerland as examples to make a brief analysis

(1) DK series carding machine of Germany truzler company: DK2 carding machine uses 5.6 g/m for spinning C 17.15 tex, while DK760 carding machine uses 5.46g/m for spinning cjl4tex yarn, 5.175g/m for spinning 92.5 tex and 100.5 tex of rotor yarn, 3.976g/m for spinning CJ 14.58 tex and 4.858 g/m for spinning CJ 29.15 tex, Dk803 carding machine spins 29.15 tex rotor yarn with 5.83 g/M ration, DK903 carding machine spins Microfiber with 5 g/M ration, and DK903 carding machine spins cotton with 5.55 g/M ration

(2) Swiss Rieter carding machine: C1/3 carding machine uses 4.72g/m to spin T/c13tex, C4 carding machine uses 4.5 g/m to spin cj14.58 tex, the company has advanced technical equipment and professional testing team, 5.6g/m to spin C 60 tex~c 30tex, 5g/m to spin rotor yarn 83.3 tex, 4.26g/m to spin C 28 tex, 4.4g/m to spin cjl4.58tex, The quantity of combed yarn spun on C10 carding machine is 4.46 g/m, and the quantity of CJ 9.7tex spun on C50 carding machine is 4.5 g/m

it can be seen that in the process of high-yield carding machine, whether spinning coarse, fine count yarn or spinning superfine fiber, the sliver quantitative range changes little, and the way to improve the output mainly lies in improving the output speed. The same conclusion can be reached by analyzing the sliver quantitative used in the actual production of carding machine in other companies

2 discussion on the value range of sliver ration

some researchers in China believe that the sliver ration should be 4 g/m-5.4 g/m on the spinning carding machine with a output of 20kg/h~30kg/h. Zhang believes that [2] in the contemporary blowing carding system, the carding sliver ration should be 4 g/m-5 g/m. Zheng textile machine fa221a carding machine adopts a ration of 4.5 g/m-5 g/m in different manufacturers (see Table 8)

the sliver weight recommended in the cotton spinning manual is 3.8 g/m-5g/M (the output of A186C carding machine is 15 kg/h~25 kg/h), and that of a190 duplex carding machine is 4.5 g/m. The data shows that ~5.2g/M (the output is 32kg/h~35 kg/h, spinning rotor yarn is more than 32tex). The empirical output of Japan is 23 kg/h. The carding machine can use 4.7 g/M ~ 5.3g/m

truzler advocates using high-speed output technology to improve output. Its dk803 carding machine uses 4 g/m for cjl4.58 tex yarn, 4.858g/m for cj29.15 tex yarn, and 5.83g/m for C 29.15 tex yarn. In the technical parameters of DK903 carding machine, the sliver ration range is 4 g/M-10 g/m. when processing superfine fibers, the sliver ration is 5 g/M and when spinning cotton (75.2 kg/h), the sliver ration is 5.55g/m. It can be seen that the process design idea is: generally, the weight of 4G/m-5.5 g/M is used, and only when spinning rotor yarn, the weight of 5.83 g/M is used

Lida Company also advocates increasing the output by increasing the output speed, but believes that the quantity should not be too light. The test of reference [4] shows that the sliver staple and yarn quality of C4 machine with 3.4 g/M ration (the same output) are not as good as that with 4.5 g/M ration. The literature also confirms that the CV value of sliver evenness of C4 carding machine is poor when the ration is too light. The test (see Table 9) shows that using 5 g/m to quantify sliver lint and impurities on C50 carding machine (under the same output conditions) is better than using 4G/m, but the sliver neps and evenings are on the contrary. The quantitative requirements of C50 carding machine are generally above 4.2g/m

through a large number of data statistics, the quantitative value range of green strips is studied. The frequency histogram of the quantitative value range of green strips is shown in Figure 1

from this histogram, we can also roughly see the actual value range of the quantitative value of the sliver. In actual production, the quantitative value of the sliver is generally between 3.6 g/M and 6.7g/m, of which the value below 4G/M accounts for 13%, 4G/m-5.2 g/M accounts for 73%, and the value above 5.2 g/M accounts for 14%. It can be seen that the actual sliver quantitative value range of high-yield carding machine is mainly concentrated in the range of 4G/m-5.2g/m

for the convenience of research and discussion, according to the actual development, the author suggests that the definition of light weight is below 4G/m, the definition of medium weight is 4G/M ~ 5.2g/m, and the definition of heavy weight is above 5.2g/m. When using a high-yield carding machine, according to the above analysis, it is best to adopt a medium quantity and fast process route

3 reasons for little change in sliver weight of high-yield carding machine

carding machine output =kgv (1)

where: C is sliver weight, V is output speed, K is constant

it can be seen from formula (1) that if you want to increase the output, you can increase both g and V. in view of the fact that contemporary high-yield carding machines adopt the method of increasing the doffer output speed to increase the output, and the quantitative quantity is only slightly increased, with little change, the following analysis is made

3.1 limitation of total drafting multiple in the spinning process

when the sliver weight is increased quantitatively, it means that the drafting multiple will increase during the spinning process. We know that no matter how perfect the drafting mechanism is, the increase of drafting multiple will sharply increase the number of yarn defects [7]. Spinning practices at home and abroad have confirmed this

the research of Xiong Wei et al. [8], no matter whether the raw materials are good or bad, when the sliver weight is increased, all indicators of the spinning quality of spinning the same number of yarn are quantitative light better than quantitative heavy (the quantitative range is 3.5 g/m~5.0g/M). When the raw materials are poor, this difference is even greater. The relevant tests of foreign Simpson, artztl et al. Also show that, The yarn defects of heavy weight green sliver spinning are always higher than those of light weight green sliver spinning. The quantitative range of Simpson test is 3.54 g/m-5.67 g/M; The quantitative range of artzt is 4G/m~6.7 g/m

therefore, from the perspective of drafting in the spinning process, the quantitative increase of sliver is unfavorable to the final quality of yarn, so the quantitative increase of sliver should not be too heavy, which is also the basic principle to be always followed in the development and use of high-yield carding machines in the future

3.2 it is beneficial to reduce the needle load of cylinder and improve the doffer transfer rate

according to the research of baurzonov Nawaz, P. grosberg [11, 12, 13] and others, when the doffer speed is increased, the transfer rate is increased. Due to the improvement of the process and manufacturing level of contemporary high-yield carding machines, such as the new tooth type and special treatment method of doffer card cloth, the fiber transfer is greatly improved compared with the traditional carding machine. The fiber density on the cylinder decreases, the load decreases, and the amount of free fiber decreases. This is because the increase of doffer speed is equivalent to the increase of the contact probability between doffer needle teeth and the fiber on the cylinder, which is conducive to fiber transfer. In addition, the reduction of fiber load on the doffer needle cloth (because the sliver weight is reduced) also reduces the pressure on the fiber on the cylinder needle cloth, which will make the fiber on the cylinder needle cloth float up, the fiber density decreases, and the fiber is easy to transfer. At the same time, because the cylinder load is reduced, the amount of cover flower is also reduced [14], which will improve the carding capacity of the carding machine (cylinder cover area), so it is conducive to the improvement of carding quality. This is another reason why modern high-yield carding machines adopt fast and sliver quantitative changes little

however, the sliver weight should not be too light. If the sliver weight is too light, it means that the doffer speed is too fast, so the amount of free fiber will become too small. Because the carding capacity of contemporary high-yield carding machines is strong, the carding strength of the fiber will increase, which will cause fiber damage and lead to the increase of short fibers. Relevant tests show that when the light weight of 3.4g/M is used on C4 carding machine (which is already lower than the sliver weight range of C4 carding machine), The short fiber rate is higher than 4.5g/m. This proves that too light weight will indeed cause fiber damage, so the contemporary high-yield carding machine should not use too light weight. In addition, too light weight will cause poor cotton holding force and cotton flutter, which is also not conducive to the formation of cotton and the high-speed output of sliver. In order to increase the strength of sliver, modern high-yield carding machines have taken technical measures to appropriately increase the sliver weight, which is also an important reason for the slow increase of sliver weight of high-yield carding machines

3.3 improvement of high-speed stripping system

according to the above analysis, if the carding machine wants to produce high yield, it must increase the doffer speed. However, when the output speed increases, the sliver will be broken due to cotton fluttering, head surging and other reasons. Therefore, high-yield carding machines at home and abroad are developing high-speed cotton guiding devices to strengthen the conveying strength of sliver and improve the stable conveying capacity of sliver. According to the test, the cotton guiding device is not used on DK2 machine, Although a higher quantity is used (to strengthen the strength of cotton), when the doffer speed is 38 R/min, there are five broken ends in half an hour, while after the cotton guide device is used, when the doffer speed is 50 R/min, there is no broken end in half an hour, which can be seen

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